The present invention is directed toward the art of support structures for parabolic reflectors, and more particularly concerns a support structure for a large parabolic reflector which is intended primarily for use as a solar reflector and which is comprised of a large number of small reflecting sections arranged into a paraboloid.
Large dimension parabolic reflectors, on the order of twenty feet in diameter and larger, have historically been proposed for use in a variety of applications, including use in a solar collection system. However, large dimension parabolic reflectors have always been difficult and expensive to manufacture and hence are presently considered impractical, except perhaps in special purpose applications, such as large telescopes.
In addition to the cost involved in producing such a parabolic reflector per se, the support structure for such reflectors also is complicated and expensive. Additionally, the support structure must be designed for the particular reflector application, and a support structure suitable for one application would not necessarily be suitable for any other reflector applications.
For instance, those support structures which have been developed for parabolic reflector telescopes are not suitable for solar collector applications, wherein the reflective surface must be as open as possible to the sun, and wherein the support structure must be capable of withstanding harsh weather environments, including high winds and hail, without damage to either the support structure or the reflector.
Other large-dimension curved structures besides parabolas have been constructed using a plurality of relatively small size plane sections of various forms. An example of using relatively small sections to construct a spherical structure is shown in U.S. Pat. No. 2,978,704, titled: Random Structural Devices. As suggested herein, large dimension parabolic reflectors can also be constructed with small-size sections, at considerable cost savings over a single surface reflector.
Although such a construction technique may significantly reduce the cost of producing a parabolic reflector per se, the problems of adequately supporting and protecting that structure, especially under extreme weather conditions, remain. To the best of the inventor's knowledge, there is very little information available concerning support structures for large-dimension parabolic reflectors intended for outdoor use, especially where the reflector comprises a plurality of relatively small sections and is intended for use as a solar collector.
Necessarily, such a support structure must have the proper strength in order to support the plurality of reflecting sections without breakage during normal operation, and must be capable of protecting the reflecting sections in weather extremes. It must further interfere only minimally, if at all, with the amount of sun reaching the reflecting surfaces of the individual sections.
Additionally, such a support structure should be relatively inexpensive, so that the combined support structure-parabolic reflector may be economically practical as a solar collector. Further, the support structure should be relatively simple and inexpensive to install on site, and must be capable of accurately tracking the sun in its movement across the sky.
Accordingly, it is a general object of the present invention to provide a support structure for a parabolic reflector which overcomes one or more of the disadvantages of the prior art noted above.
It is another object of the present invention to provide such an apparatus which is relatively simple to install on site.
It is a further object of the present invention to provide such an apparatus which is capable of withstanding the stresses of weather extremes.
It is another object of the present invention to provide such an apparatus which is capable of supporting a parabolic reflector without counterweights.
It is an additional object of the present invention to provide such an apparatus which is capable of supporting a large-dimension parabolic reflector comprised of a plurality of relatively small-size reflecting sections.
It is yet another object of the present invention to provide such an apparatus which is capable of supporting a multiple-section parabolic reflector over an extended period of time without damaging the individual sections.
It is a still further object of the present invention to provide such an apparatus which permits the individual sections comprising the parabolic reflector to be separately focused.
It is another object of the present invention to provide such an apparatus which is capable of tracking the sun with the parabolic reflector.